The BBC is to broadcast a documentary that will raise questions over Pope John Paul II’s relationships with women, including exploring whether he may have fallen in love with a married Polish-American philosophy professor.

'How could I fall in love with a middle-aged clergyman?'

Anna-Teresa Tymieniecka

The Panorama programme, set to air on Monday night, is understood to have unearthed a trove of letters between the late Pope and Anna-Teresa Tymieniecka, a philosopher who worked on a book with the pontiff in the 1970s, when he was still known as Cardinal Karol Wojtyla.

Tymienecka, who died in 2014, is said to have engaged in a feverish four-year correspondence with the future pontiff during the period, when the pair were in their fifties, as they collaborated on his philosophical treatise, The Acting Person.

Anna Teresa Tymieniecka, a Polish-born American philosopher

The academic, who was born into an aristocratic Polish family, married a Harvard economics professor, Hendrik Houthakker, in 1955, but is said to have remained a devoted friend of the Pope, even inviting the future pontiff to the couple’s Vermont home, until his death in 2005.

Carl Bernstein, the renowned American journalist who wrote a 1996 biography of the pontiff, credits John Paul's collaboration with Tymiencka, whom the writer describes as “a vivacious, cosmopolitan Polish aristocrat” as having “helped bring him the international stature that was helpful in his becoming Pope”.

The author conducted lengthy interviews with the academic, in which she denied any romantic entanglement with the Pope, saying that their relationship was merely “mutually affectionate”. She added: “How could I fall in love with a middle-aged clergyman?”

Pope John Paul II's travels took him to more than 120 countries, where he argued for peace and denounced human rights abuses Photo: AP

Friends of Tymieniecka told the journalist that she did feel a romantic pull towards the future pontiff. One close friend, the late Harvard professor George Hunston Williams, is quoted as saying that the Pope was not aware of the depths of her feelings towards him. He told the author: “I don't think he understands what she's coping with when she's in his presence. A magnet pulls steel particles. He doesn't know that.”

'He had a way of moving, a way of smiling, a way of looking around that was different and exceedingly personal'

Anna-Teresa Tymieniecka

Tymieniecka did not hide her affection for the Pope, describing her feelings towards him to one biographer by saying: "He had a way of moving, a way of smiling, a way of looking around that was different and exceedingly personal. It had a beauty about it.”

She added: “If there is one trait of character which I can observe in him, it is love of contradiction. He's extremely proud, terribly sensitive to pride. This is an extremely multifaceted human being, extremely colorful. People around him see the sweetest, most modest person. He is by no means as humble as he appears. Neither is he modest. He thinks about himself very highly.”

Wanda Poltawska with Pope John Paul II, when he was still known as Cardinal Karol Wojtyla

Poltawska, 94, a psychiatrist who survived imprisonment in a Nazi concentration camp, caused a storm in the Vatican, in 2009, when she released a 570-page volume of intimate correspondence between the pair.

The future pontiff met Poltawska in the 1950s, when she sought out a priest to help her come to terms with the terrible suffering she had seen and endured, including becoming a victim of the Nazis forced medical experiments. The pair maintained a close friendship, and she was one of a handful of people present at his death.

The book, which created such a stink that it is said to have delayed the pontiff’s beatification, revealed emotional exchanges in which he addressed Poltawska, who was married, as “My Dear Dusia”, and signed his letters “Br” – short for brother.

Wanda Poltawska visited the Pope in hospital in Rome, after an assassination attempt Photo: AFP/GETTY IMAGES

'We got to know each other in work, not in anything else'

Wanda Poltawska

At the time of the tome’s publication, Vatican officials insisted that Poltawska had exaggerated her closeness to the Pope. Cardinal Stanislaw Dziwisz, John Paul’s private secretary, said that the pontiff had a gift, “to make all those who were dear to him feel like they had a special relationship with him.”

He added: "The difference is that Ms. Poltawska exaggerates in her attitude, and the expressions and display of her behavior are inappropriate and out of place.”

The correspondence led to rumours of a romantic entanglement, which Poltawska denied. She told reporters: “"What is wrong in a priest's friendship with a woman? Isn't a priest a human being? We worked together on the same thing. We got to know each other in work, not in anything else.”

Vatican sources said that they were aware of the BBC’s interest in Poltawska. One Vatican official said: “There was never any suggestion of wrongdoing. It’s not like they had a secret lovechild or anything.”